46 Forestry Quarterly. 



(Diameter of 4 in. at breast height). As early as the first season 

 of growth, decimation by disease begins. The infection, mainly 

 due to fungi of various sorts, spreads from the parent stump 

 upward and was observed to be most in evidence at the base of 

 the shoot. A large swelling at this point frequently occurs and 

 the tissues within become honey-combed in appearance and dis- 

 integrate through the enzyme of the fungi. Death results from 

 the severance of the vital connecting-vessels and tissues or by the 

 mechanical forces of snow or wind. 



There are two serious fungus enemies of the Chestnut, both 

 attacking the heartwood of living trees. The Sulphur Mushroom 

 (Polyporus sulphureus) eats out the heartwood causing "brown 

 rot" and the Honey Mushroom (Agaricus melleus) sends it char- 

 acteristic black mycelium into both the food conducting vessels, 

 and the sapwood. It appears that young sprouts are practically 

 susceptible to attacks from the latter, being killed by it in large 

 numbers. 



Decimation by Intolerance of Species. — Since the sprout does 

 not depend upon light for its food supplies during the first year 

 or two, it is relatively tolerant. When the stock of nourishment 

 in the stump lessens appreciably this condition alters, and Chest- 

 nut sprouts, as already shown are highly intolerant. The change 

 is both continuous and rapid. During the second year there is 

 a thinning in the average colony, usually greatest when the sprouts 

 are crowded so as to receive neither adequate food materials nor 

 sufficient light for independent growth. In both good and poor 

 situation a difference in the amount of height growth during the 

 second and third years has been observed corresponding to full or 

 partial light supply. The rate of decimation up to about the 

 fifth year is very rapid, commencing to diminish however at 

 about the third year; at about the eighth year the number of 

 dominant sprouts to a colony does not usually exceed four to six. 

 The chief factors which prevailingly influence the rate of decima- 

 tion are health and age of parent stump, supply of light, and site 

 quality. It is a common experience in a coppice growth of four 

 to seven years in age to find frequently large clumps of Chest- 

 nut sprouts consisting mostly of a bunch of dead and dry sticks 

 with the bark loose and clinging in tattered shreds. This may 

 in part be the result of intolerance but likewise an explanation may 

 be found in the inherent disposition to short life coming from an 



